Inspired by folks like Gant Grimes and Melissa Byers, I thought I'd tell you folks about my current experiment with Intermittent Fasting, and how it's going.

Goals & Plan
I'm coming off a bulking cycle where I gained about 13 pounds, most of which was fat. I was not happy with this cycle. As a tall skinny guy, I do not gain weight easily - those pounds were a battle. I told myself I'd turn around when my waist hit 34", as I don't like the pudgy feeling I get above that, and as a rock-climber I REALLY dislike hauling any unnecessary weight up the wall. It makes a huge difference.

So the goal: get back down to a 32" waist ASAP, so I can turn around and try the muscle thing again, hopefully more efficiently next time. Not sure what this amounts to in pounds, but I'd guess 10 or so.

The plan: Fast for 16 hours, 5 times a week. 8pm to noon the next day. Shoot for under 2500 kcal/day, eating more than 160g/protein a day (1g per pound LBM), but not more than 150g carbs (100g would be ideal). Make up the difference with fat. On fasting mornings, do a HIIT-style workout (usually burpees in sprint sets) followed by 30 minutes or so of easy cardio. This is in addition to regular CF WODs in the evenings 2-3 times a week, as well as climbing and some compound heavy lifting (ie, deadlifts/squats) to try and maintain muscle.

Midway through the week, I noticed my weight had plummeted almost 9 pounds. I'm guessing this was water weight loss brought on by the shock of the lower carbs + IF. For the next few days, I was endlessly thirsty and drank copious amounts of water, and the weight went back up to a more reasonable level. I'm still more thirsty than usual, I'd say, so it's probably still correcting itself.

The fasting itself isn't particularly difficult. The hardest part has been trying to get accustomed to black coffee in the mornings.

On a few days I had to supplement my dinner with a protein shake in order to meet that day's protein requirements. I don't like to do this if I can avoid it.

As for energy, I wouldn't say it's "through the roof" but it's sufficient for the morning workouts. I never suffered lightheadedness during a workout, although I did feel a little nauseated rowing on Monday morning (Monday was rough - probably took on too much for the end of the workout week).

So I'm not exactly sure whether it was lipidolysis energy release or just plain ol' endorphins, but I noticed an elevation of my mood and a "second wind" about 5 minutes after the burpees one morning, doing some easy jogging on the treadmill. I kept an inner eye open for these types of mood swings, and noticed another one after about 15 minutes (the treadmill is deadly boring, so introspection of this type is not difficult). There were a couple minor ones every five minutes or so after that, but nothing as dramatic as the first two. It was an interesting feeling of minor elation and personal satisfaction, as well as strength. I wonder if that was the result of my body releasing energy to my muscles from the fat stores? At any rate, apart from the tedium of the treadmill, it felt good.

It is currently my intention to try and continue to IF when I turn this around to attempt weight gain. I figure I'll need to add about 1,000 calories and another 40-50g protein daily. Still not totally sure how I'll do this.

I hit PR's in both push-press and deadlifts last week, one of which (push-presses) was while in a fasted state.